There are three main components to most solar cookers, or you could say three main principles to effective solar cooking; these being:
1 Concentration (reflection, or reflectance)
2 Absorption (ability to attract or hold heat.
3 Retention (means or capacity to retain heat)

Solar cooking is done by means of the suns UV rays.A solar cooker lets the UV light rays in and then converts them to longer infrared light rays that cannot escape. Infrared radiation has the right energy to make the water, fat and protein molecules in food vibrate vigorously and heat up.